HVAC Relays 101 3D

This 3D animation will go through the 101 of of relays in HVAC systems, exploring key components like the coil and contacts, as well as how relays work and why we use them. This 3D video also covers components that are similar to relays.

Relays are electrically operated switches that generally allow a lower-voltage control circuit to control higher-current circuits to help turn things on and off safely. The main component of a relay is a coil or electromagnet, and there is also a series of electrical contacts. When current passes through the coil, it generates a magnetic field that moves a metal armature, opening or closing the attached contacts (also known as switches or contact points). These contacts allow or disrupt the flow of electricity, depending on whether they're closed or open, respectively. These contacts may be normally open (NO) and close when the coil is energized or normally closed (NC), which open when energized. Relays provide isolation between the control circuit and the circuit being controlled. That is why we can control 240v components with much safer 24v controls in residential HVAC systems.

We must pay attention to the coil or control voltage rating, contact voltage, and amperage ratings to make sure we have the right relay for the application.

Two common relay types we see in HVAC include 90-340 and ice cube relays. 90-340 relays are double-pole, double-throw (DPDT) relays with two sets of contacts (one NO and one NC in isolated rows, making them "dry contacts") and eight terminals; they are multi-purpose relays that can control components that draw less than 15 amps, like fan motors. The coil pulls the switch contacts to change the states of the contacts. Ice cube relays have a clear casing, a coil, an armature, and contacts.

Some controls that function like a relay include contactors, which have contact points and can handle current up to 40 amps and often control compressors; their contacts are normally open and close upon energizing. Motor starters are like large contactors that come with an overload and are designed for starting and stopping motors, providing control and overload protection.

MOSFETs also work similarly to relays, but they have different components and switch electronically rather than physically, and their three components are the gate, drain, and source. Stack sequencers use physical components to control sequences in electrical heaters and fans; they consist of a heater and a bi-metallic disc for on/off delays.

You can test many of these controls for continuity with a multimeter.

[cptamerireborn]

Totally awesome graphics! Makes everything very clear!

[quietgameplays]

As a green tech on his 2nd year on the field, I have learn so much from this channel. I really appreciated the instructor and the person that does the 3d views. Thank you guys

[donaldbakerakathedonaldaka]

Outstanding presentation! Thanks Bryan and HVACR School

[altamashshah]

It is very well explained, timing and animation are extra ordinary. I understood alot after my second time viewing. The more you view the video the deeper understanding you get.Thumbs up and keep up the good work.

[JoshuaVelasco-zjuq]

Super amazing video! Something I thought was interesting was stack sequencers and that they control electric heaters and fans.

[EverythingHVACR]

This is great content. Thanks, Bryan!

[MolecularHeckler]

relays and wiring diagrams... finally my two faults in one video! TY!!

[frankminisplitking]

Awesome training, from an awesome operation! I retired a couple years ago from the military, and now am part owner of an HVAC company in Austin, Tx. I watch all your videos on how to be a great HVAC company! You are a pro! And great trainer! Super professional!

[jimmyphillips]

Game changing for new techs, thank you!!

[AriZonaKDD]

videos are getting better and better. keep up the good work

[lunaticg]

very cool, nice presentation and music too

[ELECTROxigeno.]

Exelent Animation & vídeo, tks, 🎩

[DoraYbarra-qg]

excellent graphic for beginners like me.

[victorgarzon]

Thank you very much, I highly appreciate it, God multiple your businesses.

[joaquinmaciel]

This is great content, I'm gaining lots of knowledge.

[zemhrethagos]

I wish you are my instructor, man. While some one does not show me shuch good instructing.

[hugossotos]

Simplifies the explanation without a doubt, Im more of a real life type of guy, where you apply theory to real life situations .

[zokotziggy]

U just get me as a new follower . Thank you

[TheDroppedAnchor]

Wow! Subscripting. Great production values.

[dorhocyn]

So if a relay is basically a switch and I had a spare relay laying around, could I install it on my Glock? Or would a relay make my Glock illegal?